Message-ID: <4E40AC9B.9090400@2ndquadrant.com>
Date: Mon, 08 Aug 2011 23:42:19 -0400
From: Greg Smith <greg@2ndquadrant.com>
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To: mark <dvlhntr@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: benchmark woes and XFS options
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I think your notion that you have an HP CCISS driver in this older 
kernel that just doesn't drive your card very fast is worth exploring.  
What I sometimes do in the situation you're in is boot a Linux 
distribution that comes with a decent live CD, such as Debian or 
Ubuntu.  Just mount the suspect drive, punch up read-ahead, and re-test 
performance.  That should work well enough to do a simple dd test, and 
probably well enough to compile and run bonnie++ too.  If that gives 
good performance numbers, it should narrow the list of possible causes 
considerably.  You really need to separate out "bad driver" from the 
other possibilities here given what you've described, and that's a low 
impact way to do it.

-- 
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us